If a warrior fights valiantly, he will win glory (kleos) that will live after his death. It is because human beings are mortal and survive only as pale shades in Hades that they must strive to achieve something in life that will cheat death of all its prize.
Sullivan identifies heroic kleos as a psychological compensation for mortality, the structuring motive of archaic Greek valor.
, Psychological and Ethical Ideas What Early Greeks Say, 1995thesis